The invention relates to a color television transmission (or data storage) system having time-division multiplex encoding, the system comprising a data generator, at least one data receiver and a transmission (or data storage) channel arranged between the generator and the receiver, the data generator comprising a signal source for producing signals containing luminance, chrominance, synchronizing and identification information and an encoding circuit for supplying at an output, a time-division multiplex encoded signal for transmission via the transmission channel or storage in the data storage channel, this time-division multiplex encoded signal, containing, during a number of p line periods of a field period, the non-compressed luminance information, and, during a number of q other line periods, the time-compressed chrominance information associated with this luminance information, the number p+q being less than the number of m line periods forming a field period, the data receiver comprising a decoding circuit coupled to said channel and suitable for supplying signals containing at least luminance and chrominance information which largely corresponds to the data produced by the signal source in the data generator. The invention also relates to a data generator and receiver suitable therefor.
Such a system for, more specifically, transmission is described in a published report "Document 10-11S/106-E, Sept. 23, 1983" published by the Comite Consultatif International des Radiocommunications, entitled "Draft new report: Satellite transmission of Multiplexed Analogue Component (MAC) television signals" and presented during a meeting of the C.C.I.R. in Geneva, September 1983. The report describes several variants of so-called MAC-picture coding. For some variants, it holds that in the data generator, which is in the form of a transmitter the luminance and the chrominance information, which each comprise two components per line period, are each subjected to time compression. In the time-division multiplex encoded signal, the luminance information associated with each line period is present in the time-compressed form. The picture information per line period in the time-division multiplex encoded signal is sequentially composed from the time-compressed chrominance information components associated therewith.
The above-mentioned report also describes variants having time-division multiplex encoding at the field frequency. In one variant, only the luminance information is transmitted during a plurality of line periods in the field period, while during other line periods only the associated time-compressed chrominance information components are transmitted. The other line periods can be divided into two groups, one of the two chrominance information components being supplied during the first group, while the other chominance information component is supplied during the second group of line periods. The first group may occur at the beginning of the field period, whereafter the line periods having the luminance information and thereafter the second group of line periods having the chrominance information occur.
In still further variants, one of the two chrominance information components is supplied during a number of line periods. During the subsequent line periods the picture information is sequentially composed for each line period from the other chrominance information component and the luminance information. The three information components are time-compressed. The transitions between the different information components can, moreover, be variable.
In the receiver, the time-division multiplex encoded signal is derived from the signal received via, for example, the satellite connection and applied to a complementary decoding circuit which, with the aid of the synchronizing and identification information, produces a time-decompression for the information transmitted in time-compressed form.
In the foregoing, a transmission channel in the form of a satellite connection is mentioned as an example. It will be obvious that the transmission of information can also be effected with the aid of a data storage channel. Such a storage channel comprises data storage and data reproducing equipment, such as, for example, tape and record recording and reproducing devices.